Field of Invention
The present invention relates to a power supply apparatus. More particularly, the present invention relates to the internal structure of a power supply apparatus.
Description of Related Art
With people's increased demand to the intelligent life, the society's need to data processing is also growing. The global energy consumption spent on data processing averages thousands or even tens of thousands kilowatt-hour (KWH); and a large scale data center may occupy tens of thousands square meters. Therefore, a greater efficiency and higher power density are the key index for the healthy development of this industry.
The key component of the data center is the server, which has a main board that usually composed of data processing chips such as CPU, chipsets, memory, etc., and the power supply and necessary peripheral components thereof. With the improvement of the processing capability of the server unit volume, the numbers of these chips and the integration level thereof are also increased, which results in the increase of the space occupied and the power consumption. Therefore, the power supply for supplying these chips (also referred to as the main board power supply because it is disposed on the same main board as the data processing chip is) is expected to exhibit greater efficiency, higher power density and more compact volume, so as to realize the energy-saving of the whole server or event the whole data center and reduction of the floor space.
In the server, the main board PCB is configured to transmit the energy and signal. On the main board PCB, a data processing chip and a power supply thereof are disposed. The height of the casing of the server is often a standard value, which is defined using the industrial standard “U”; for example, 1U, 1.5U, 2U, etc. (1U=1.75 inch=44.45 mm). For example, for a server with a height of 1U (about 40 mm; the actual size of the 1U device may vary due to the fit tolerance), the main board is a PCB consisting of 6 to 50 layers, which is very expensive to manufacture. In the case where the height of the server casing is limited, in order to ensure the expected efficiency, by reducing the area that the main board power supply occupies on the main board (that is, the horizontal area of the main board power supply), it is possible to reduce the over volume, increase the power density, and accordingly, lower the manufacturing cost. In the present disclosure, the power of the power supply unit horizontal area is referred to as the “power pressure”.
When using the same technology level in designing a power supply having a power of Po, the greater the volume (V) of the power supply, the easier to achieve a higher efficiency; that is, the power efficiency is positively proportional to the volume (V). The volume (V) equals to the product of the height (H) and the horizontal area (S). The power pressure (Pp) equals to Po/S. If the efficiency is fixed at a specific level (meaning the efficiency is kept the same), the following relationship between the power pressure (Pp) and the height (H) could be derived: the greater the H, the greater the Pp. In other words, to improve Pp, we should focus on the utilization of the height (H) for a solution. Of course, if the goal is to pursue the efficiency, the height should be properly utilized based on the foregoing rationale. Therefore, how to utilize the height is the key to address both the power pressure (Pp) and the efficiency.
The thickness or height of the main board power supply can be as thin as 7 mm or even less; hence, when the height of the server is limited to, say 1U, there are more than 20 mm of space height above the power. In this case, the efficiency can be 90% or higher, since the power consumption thereof is only a fraction (such as 10%) of the data processing chip, in fact, it is possible for it to handle the heat dissipation issue without using a heat dissipation unit. In this way, the space above the main board power supply is not adequately utilized.
Generally, there two ways to manufacture the main board power supply. The first one uses a PCB as the bearer on which individual components are installed. After years of efforts, this type of main board power supply achieves satisfactory efficiency and power density. Yet, since the components are individually installed, there should be necessary space or safety distance between components, thereby limiting the further size reduction of the horizontal area; also, the uneven height would affect the subsequent handling of the heat.
The other way to manufacture the main board power supply is to use certain packaging technique to integrate each components of the power supply into a quite regular element. By using such packaging techniques, the power density is significantly increased with satisfactory efficiency; also, such regular shape is advantageous for the subsequent handling of the heat; thereby providing an appropriate solution. However, said packaging technique realize the volume reduction and power density improvement by lowering the height of the main board power supply, and hence, it focuses on decreasing the height based on the original horizontal area. Therefore, this solution is only one of the solution for pursuing a better power density; however, it cannot adequately address the improvement regarding the power pressure of the main board power supply.